1 Muscles Flashcards
Locomotion
Eg in paramecium
Hydra
Humans
Locomotion, movement related
Some of the movements result in change of place or locomotion
Cilia helps in movement of food through cytopharynx and in locomotion as well
It’s tentacles for capturing its prey and also use them for locomotion
Limbs
All locomotion are movement but not all movements are locomotion
Amoeboid movement eg ,also eg
Effected
Cililary movements occur most
—— movement of cilia in our trachea helps
Also eg
Macrophages and leukocytes in blood exhibit , cytoskeleton elements like micro filaments
By pseudopodia formed by streaming of protoplasm
Of our internal tubular organs which are lined by ciliated epithelium
Coordinated, us in removing dust particles and some of foreign substances inhaled along the the atmospheric air
Passage of ova through the female reproductive tract
The property of muscles used for locomotion in human
Flagella movement helps in
Locomotion requires
Contractile
Swimming of spermatozoa,
Maintained of water current in canal system of sponges
Locomotion of protozoans like euglena
A perfect coordinated activity of muscular , skeletal , neural system
Muscles study
All muscles develop from
Special properties like
Body weight contributed by muscle
Myology / sarcology
Mesoderm except muscle of ciliary body and iris (ectodermal)
Excitability, contractility , extensibility , elasticity
40-50%
Skeletal muscles ____ found at regular interval so also called and also
Primarily involved in
Endomysium /
Perimysium /
Fasciculi
Transverse muscle , striped or striated , voluntary
In locomotory actions and changes of body posture
Myofibril , Muscle fibre covered by a layer of Areolar ct
Fasiculus , each fasiculi covered by layer of Areolar ct
Many muscle fibre are combined to form a group of
Muscle
Epimysium /
Tendon , attached with
Sacrolemma , contains
Each muscle fibre contains
,,,,,,, +nt in peripheral part
Many fasciculi combined to form
Fascia, muscle covered by a layer WIDFCT
The muscle fibres attached to a tough o cord of ct ( WRDFCT ) , a bone
Outer mem of muscle fibre , collagen fibres
Multinucleated sarcoplasm
Nucleus and sarcoplasm
Myofibril arranged in , form(band) ,order
These band made up of , proteins
Thick filaments , thin
Isotropic band ( I band )
Parallel rows , the dark and light band , found in alternate order
Actin(I) and myosin(A) protein = Filamentous proteins
Myosin , actin
Light line or band is made up of only actin filament, these band are mono - refractive in polarised light
Z line , fn
Attached
M line
Functional unit of contraction , =
In centre of each I band is an elastic band is an elastic fibre , which bisects it
The thin filaments ( actins ) are firmly atthached to it
The thick filaments ( myosin) in A band are also held together in middle of this band by a thin fibrous membrane
Sarcomere = portion of Myofibril between two successive Z lines
In resting state
H zone
1 myosin filament
1 actin filament
Z disc made up
The edges of thin filaments ( actin ) on either side of the thick filaments ( myosin) partially overlap the free ends of thick filaments leaving the central part of myosin
This central part of thick filaments ( myosin ) not overlapped by thin filaments ( actin )
Surrounded by 6 actin filament
Surrounded by 3 myosin filaments
Actinin protein
Each Actin filament is made up of , manner
Each — is.
Tropomysin no,
Troponin
In a resting state
Two F ( Filamentous ) actins helically wounded to each other
F protein is a polymer of monomeric ‘ G’ ( globular ) actin
Two filaments of another protein , tropomyosin also runs close to F actins through out its length
A complex protein, is distributed at regular intervals on tropomyosin
A subunit of troponin masks the active binding sites for myosin on actin filaments
Troponin is made up of three subunits
In a resting state
a) Troponin I ( inhibitory unit )
B ) Troponin T( tropomyosin site )
C) Troponin C ( Ca +2 binding site )
A subunit of troponin masks the active binding sites for myosin on actin filaments
Myosin filament
Each myosin is also a
Each ______ has two important parts
Polymerised protein . Many monomeric proteins called meromyosins constitute one myosin
Meromyosin, a globular head with a shirt arm = heavy meromyosin (HMM )
Tail = light meromyosin ( LMM)
Cross arm
The globular head is an
The HMM component projects Outward st regular filaments and is known as
Active ATPase enzyme and has binding sites for ATP and active sites for actin
Mechanical is best explained by
Muscle contraction is initiated by . Motor unit
Motor end plate /
A neural signal reaching this , generates
Sliding filament theory
A signal sent by cns via a motor neuron . A motor neuron along with muscle fibre connected to it
Neuromuscular junction = the junction between a motor neuron and the sarcolemma of muscle fibre
This junction releases a neurotransmitter ( acetylcholine) which generates an action potential in sarcolemma
Neurotransmitter spreads through
Increase in ___ leads to binding of
To form a cross bridge
Fn
Muscle fibre and causes the release of calcium ions into the sarcoplasm
Ca++ , of ca with a subunit of troponin on actin filament and thereby remove the masking of active sites for myosin
Utilising the energy from atp hydrolysis the myosin head now binds to exposed active sites on actin
Pulls the attached actin filaments towards the centre of A band
